This makes it okay. Zack didn't know this about himself, but a genuine apology - even though it wasn't Alec's fault - appears to make him feel a lot better. Maybe it's not the apology itself, but the acknowledgement that something nasty just happened and that Zack's feelings are valid.

He never gets that in Antillioch. Even as a kid, crying would earn him a smack in the face.

"S'okay. You didn't do it." He's still nursing his head. Pressing a palm to his forehead, Zack is trying to find that line between focussing on the topic, and not thinking too deeply. "Dunno what he wanted. Told me I shouldn't eat dead planets. M'connected to living ones, not dead ones, or something. And about how much it hurts to think. That Abe did it and why did he do it."

It takes some effort to get out even this sketchy information. the pain keeps creeping back... though at least not to the degree it just did.